To Refridgerate Or Not To Refridgerate ??

AI need help....every time I make a cake I face the same dilemma...if it is a straight forward American buttercream cake filled and frosted..I know what to do. However living in the Houston Texas climate, when clients ask for whipped fillings or mousses or cream cheese frostings...I begin to go back and forth. Everyone wants the clean finished look of fondant paired with these tasty different fillings...so how do you do all the elaborate fondant work and then put it in the fridge.?...when it comes out, the fondant is soft and collapses. On the other hand if I don't put it in the fridge....the fillings are such that cannot be left out for a long period of time?? Am I to just wait umtill right before delivery....and then rush to put all the fondant on? There has to be a better way... Help!!!....I need to know I'm not the only crazy person facing this....please let me know how you get around this!!
Thank you
Zahra.The Cake Stop